The present invention relates generally to a folding knife, and particularly to a folding knife having a locking mechanism that locks the blade in an open, deployed position and that may be used to both open and close the blade. This allows simple, one-handed unlocking and closing of the blade, with a single thumb-actuated motion. The same locking mechanism may be used for one-handed opening of the blade. In an alternative embodiment, the invention includes a spring mechanism and blade configuration that make opening the knife even easier.
Examples of folding knives may be found in the following U.S. patents: U.S. Pat. No. 1,454,665, issued May 8, 1923; U.S. Pat. No. 1,743,022, issued Jan. 7, 1930; U.S. Pat. No. 4,040,081, issued Aug. 9, 1977; U.S. Pat. No. 4,404,748, issued Sep. 20, 1983; U.S. Pat. No. 4,451,982, issued Jun. 5, 1984; U.S. Pat. No. 4,502,221, issued Mar. 5, 1985; U.S. Pat. No. 4,719,700, issued Jan. 19, 1988; U.S. Pat. No. 4,805,303, issued Feb. 21, 1989; U.S. Pat. No. 4,811,486, issued Mar. 14, 1989; U.S. Pat. No. 4,837,932, issued Jun. 13, 1989; U.S. Pat. No. 4,974,323, issued Dec. 4, 1990; U.S. Pat. No. 4,979,301, issued Dec. 25, 1990; U.S. Pat. No. 5,044,079, issued Sep. 3, 1991; U.S. Patent No. 5,060,379, issued Oct. 29, 1991; U.S. Pat. No. 5,095,624, issued Mar. 17, 1992; U.S. Pat. No. 5,111,581, issued May 12, 1992; U.S. Pat. No. 5,293,690, issued Mar. 15, 1994; U.S. Pat. No. 5,331,741, issued Jul. 26, 1994; U.S. Pat. No. 5,502,895, issued Apr. 2, 1996; U.S. Pat. No. 5,515,610, issued May 14, 1996; U.S. Pat. No. 5,537,750, issued Jul. 23, 1996; U.S. Pat. No. 5,689,885, issued Nov. 25, 1997; U.S. Pat. No. 5,692,304, issued Dec. 2, 1997; U.S. Patent No. 5,737,841, issued Apr. 14, 1998; U.S. Pat. No. 5,755,035, issued May 26, 1998; U.S. Pat. No. 5,802,722, issued Sep. 8, 1998; U.S. Pat. No. 5,822,866, issued Oct. 20, 1998; U.S. Pat. No. 5,826,340, issued Oct. 27, 1998; and U.S. Pat. No. 5,887,347, issued Mar. 30, 1999, the disclosures of which are incorporated herein by this reference thereto.
Common elements to folding knives include a handle and a blade pivotally connected to an end of the handle so that the blade pivots with respect to the handle between an open position in which the blade is extended away from the handle and a closed position in which the blade is at least partially received within the handle. In one embodiment of the present invention, a locking mechanism is formed from a post slidably mounted on the blade to engage the end of the handle to lock the blade in the open position. The post and blade are adapted to allow simple, one-handed unlocking and closing of the blade, with a single thumb-actuated motion. The post is also adapted to allow one-handed opening of the blade.
In other embodiments, which may or may not include the locking mechanism discussed above, an opening is defined through the handle so that an oversized tang portion of the blade may extend through the opening when the blade is in the closed position. An actuating spring may also be provided to operatively connect the blade and handle, such that the actuating spring urges the blade into the open position once the blade is rotated open beyond an equilibrium point. The actuating spring and oversized tang portion may be configured so that pushing the oversized tang portion into the handle causes the blade to pivot open beyond the equilibrium point so that the actuating spring causes the blade to pivot the rest of the way open.